using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;
using UnityEngine.UI;
using TMPro;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

public class pressStart : MonoBehaviour
{
    public string sceneName_toNextScene = "selectYourSongFirst";
    public string testModeSceneName = "gamePlay_gamePlay"; 
    [SerializeField] private string banflag_filePath = "C:/ProgramData/Bansonic/Caches/Bansonic_TestOutput";
    private bool banflag_exists;

    public static string testmode_audioFile_path;
    public static string testmode_bgPicFile_path;
    public static string testmode_beatmapJSON_path;

    // new: store banflag content for other scenes to read
    public static string banflagContent = string.Empty;

    // UI text to show status
    public Text statusText;
    public Text warningText;

    [Header("New UI Buttons")]
    public Button startButton;
    public Button helpButton;
    public Button closeButton;
    public Button exitButton;
    public GameObject helpContentObject;

    [Header("Fade Settings")]
    public CanvasGroup mainCanvasGroup;
    public float fadeDelay = 0f;
    public float fadeDuration = 1f;

    [Header("TMP Flashing Settings")]
    public TextMeshProUGUI flashingText;
    public float flashInterval = 0.5f;

    [Header("Start Sequence Settings")]
    public Volume globalVolume;
    public Image fadeOutImage;
    public float startButtonDelay = 6f; // 6秒后才允许点击 Start

    // polling
    private Coroutine pollCoroutine;
    private float pollInterval = 3f;

    // Start is called before the first frame update
    void Start()
    {
        // sceneName_toNextScene = "Songs_Select";
        banflag_exists = false;
        testmode_audioFile_path = string.Empty;
        testmode_bgPicFile_path = string.Empty;
        testmode_beatmapJSON_path = string.Empty;
        banflagContent = string.Empty;

        // Ensure status text shows idle
        UpdateStatus("Press Enter to continue.", Color.green);

        // Bind buttons
        if (startButton != null)
        {
            startButton.onClick.AddListener(OnStartButtonClick);
        }
        if (helpButton != null)
        {
            helpButton.onClick.AddListener(OnHelpButtonClick);
        }
        if (closeButton != null)
        {
            closeButton.onClick.AddListener(OnCloseButtonClick);
        }
        if (exitButton != null)
        {
            exitButton.onClick.AddListener(OnExitButtonClick);
        }
        if (helpContentObject != null)
        {
            helpContentObject.SetActive(false);
        }

        // Initialize fadeOutImage
        if (fadeOutImage != null)
        {
            Color c = fadeOutImage.color;
            c.a = 0f;
            fadeOutImage.color = c;
            fadeOutImage.gameObject.SetActive(false);
        }

        // Initialize Global Volume Bloom intensity to 0
        if (globalVolume != null && globalVolume.profile.TryGet<Bloom>(out var bloom))
        {
            bloom.intensity.Override(0f);
        }

        // Initialize CanvasGroup and start fade-in
        if (mainCanvasGroup != null)
        {
            mainCanvasGroup.alpha = 0f;
            StartCoroutine(FadeInMainCanvasGroup());
        }

        // Start flashing logic
        if (flashingText != null)
        {
            StartCoroutine(FlashTMPText());
        }

        // Start button delay logic
        if (startButton != null)
        {
            StartCoroutine(StartButtonActivationDelay());
        }
    }

    private IEnumerator StartButtonActivationDelay()
    {
        if (startButton == null) yield break;

        // 初始禁用按钮
        startButton.interactable = false;

        // 等待指定时间 (使用 unscaledTime 以防 timeScale 为 0)
        yield return new WaitForSecondsRealtime(startButtonDelay);

        // 启用按钮
        startButton.interactable = true;
        Debug.Log("[pressStart] Start button is now active.");
    }

    private IEnumerator FlashTMPText()
    {
        if (flashingText == null) yield break;

        float elapsed = 0f;
        while (true)
        {
            elapsed += Time.deltaTime;
            // 使用 Mathf.PingPong 在 0 到 1 之间往复
            // 除以 flashInterval 可以控制循环的速度
            float alpha = Mathf.PingPong(elapsed / flashInterval, 1f);
            
            Color color = flashingText.color;
            color.a = alpha;
            flashingText.color = color;
            
            yield return null;
        }
    }

    private IEnumerator FadeInMainCanvasGroup()
    {
        if (fadeDelay > 0)
            yield return new WaitForSeconds(fadeDelay);

        float elapsed = 0f;
        while (elapsed < fadeDuration)
        {
            elapsed += Time.deltaTime;
            mainCanvasGroup.alpha = Mathf.Lerp(0f, 1f, elapsed / fadeDuration);
            yield return null;
        }
        mainCanvasGroup.alpha = 1f;
    }

    private void OnStartButtonClick()
    {
        Debug.Log("[pressStart] Start button clicked.");
        HandleGameStartLogic();
    }

    private void OnHelpButtonClick()
    {
        if (helpContentObject != null)
        {
            bool isActive = helpContentObject.activeSelf;
            helpContentObject.SetActive(!isActive);
            Debug.Log("[pressStart] Help button clicked. Help content active: " + !isActive);
        }
    }

    private void OnCloseButtonClick()
    {
        if (helpContentObject != null)
        {
            helpContentObject.SetActive(false);
            Debug.Log("[pressStart] Close button clicked. Help content hidden.");
        }
    }

    private void OnExitButtonClick()
    {
        Debug.Log("[pressStart] Exit button clicked. Application quitting.");
#if UNITY_EDITOR
        UnityEditor.EditorApplication.isPlaying = false;
#else
        Application.Quit();
#endif
    }

    // Update is called once per frame
    private bool check_enterNextScene = false;
    private static readonly string WARNING_TEXT_CONTENT = "<color=orange>当前处于测试阶段</color><color=red>未授权版本</color><color=orange>版本号：</color><color=red>v1.0.0</color><color=orange>，请注意风险。</color>";

    void Update()
    {
        if (!(Input.GetKeyDown(KeyCode.Return) || Input.GetKeyDown(KeyCode.KeypadEnter)))
            return;

        // 如果按钮未激活 (还在倒计时)，不允许通过键盘进入
        if (startButton != null && !startButton.interactable)
        {
            Debug.Log("[pressStart] Start request ignored. Button is not active yet.");
            return;
        }

        HandleGameStartLogic();
    }

    private void HandleGameStartLogic()
    {
        bool requestTestMode = Input.GetKey(KeyCode.LeftShift) || Input.GetKey(KeyCode.RightShift);
        if (requestTestMode)
        {
            Debug.Log("[pressStart] Enter+Shift or button start requested, starting test mode polling.");
            GameConfig.testMode = true;
            if (pollCoroutine != null) StopCoroutine(pollCoroutine);
            pollCoroutine = StartCoroutine(PollForBanflagAndProceed());
            return;
        }

        // 修改为点击一次即可开始进入游戏序列
        Debug.Log("[pressStart] Start requested, initiating transition sequence.");
        GameConfig.testMode = false;
        
        if (warningText != null)
        {
            warningText.gameObject.SetActive(true);
            warningText.text = WARNING_TEXT_CONTENT;
        }

        // 启动进入游戏的异步序列
        StartCoroutine(StartGameTransitionSequence());
    }

    private IEnumerator StartGameTransitionSequence()
    {
        // 1. 0.5秒内将 Global Volume 的 Bloom Intensity 从 0 变到 3
        if (globalVolume != null && globalVolume.profile.TryGet<Bloom>(out var bloom))
        {
            float elapsed = 0f;
            float duration = 0.5f;
            float startVal = bloom.intensity.value;
            float targetVal = 3f;
            while (elapsed < duration)
            {
                elapsed += Time.deltaTime;
                bloom.intensity.Override(Mathf.Lerp(startVal, targetVal, elapsed / duration));
                yield return null;
            }
            bloom.intensity.Override(targetVal);
        }

        // 2. 结束变 3 后，将 Image 的不透明度在 0.5 秒内从 0 变到 255 (alpha = 1)
        if (fadeOutImage != null)
        {
            fadeOutImage.gameObject.SetActive(true);
            float elapsed = 0f;
            float duration = 0.5f;
            Color color = fadeOutImage.color;
            while (elapsed < duration)
            {
                elapsed += Time.deltaTime;
                color.a = Mathf.Lerp(0f, 1f, elapsed / duration);
                fadeOutImage.color = color;
                yield return null;
            }
            color.a = 1f;
            fadeOutImage.color = color;
        }

        // 3. 切换场景
        Debug.Log("[pressStart] Transition sequence complete. Loading UI_UI scene.");
        Time.timeScale = 1f;
        SceneManager.LoadScene("UI_UI");
    }

    private IEnumerator PollForBanflagAndProceed()
    {
        UpdateStatus("Waiting for banflag...", new Color(1f, 0.5f, 0f)); // orange

        while (true)
        {
            bool found = check_banflag_testBanflag();
            if (found)
            {
                UpdateStatus("Banflag detected. Loading test mode...", Color.green);
                // small delay to show status
                yield return new WaitForSeconds(0.5f);
                AsyncOperation asyncLoad = SceneManager.LoadSceneAsync(testModeSceneName);
                while (!asyncLoad.isDone)
                {
                    yield return null;
                }
                yield break;
            }
            else
            {
                UpdateStatus("Waiting for banflag...", new Color(1f, 0.5f, 0f)); // orange
            }

            yield return new WaitForSeconds(pollInterval);
        }
    }

    private IEnumerator LoadSceneAsync(string sceneName)
    {
        AsyncOperation asyncLoad = SceneManager.LoadSceneAsync(sceneName);
        while (!asyncLoad.isDone)
        {
            yield return null;
        }
    }

    private void UpdateStatus(string message, Color color)
    {
        if (statusText != null)
        {
            statusText.text = message;
            statusText.color = color;
        }
        Debug.Log(message);
    }

    private string NormalizeToForwardSlashes(string path)
    {
        if (string.IsNullOrEmpty(path)) return string.Empty;
        try
        {
            // Get full absolute path to remove any relative segments
            string full = Path.GetFullPath(path);
            // Replace backslashes with forward slashes
            string fwd = full.Replace('\\', '/');
            // Collapse multiple slashes into single
            string collapsed = Regex.Replace(fwd, "/{2,}", "/");
            // Remove trailing slash except when path is root like "C:/"
            if (collapsed.Length > 3 && collapsed.EndsWith("/"))
                collapsed = collapsed.TrimEnd('/');
            return collapsed;
        }
        catch
        {
            // Fallback: replace backslashes and collapse
            string f = path.Replace('\\', '/');
            string c = Regex.Replace(f, "/{2,}", "/");
            if (c.Length > 3 && c.EndsWith("/")) c = c.TrimEnd('/');
            return c;
        }
    }

    // returns true if banflag detected
    private bool check_banflag_testBanflag()
    {
        try
        {
            // reset previous results
            banflag_exists = false;
            testmode_audioFile_path = string.Empty;
            testmode_bgPicFile_path = string.Empty;
            testmode_beatmapJSON_path = string.Empty;
            banflagContent = string.Empty;

            if (string.IsNullOrEmpty(banflag_filePath))
            {
                Debug.LogWarning("banflag_filePath 未设置");
                UpdateStatus("Error: banflag path not configured", Color.red);
                return false;
            }

            string filePath = Path.Combine(banflag_filePath, "test.banflag");
            if (!File.Exists(filePath))
            {
                Debug.LogWarning($"未找到对应 banflag 文件: {filePath}");
                return false;
            }

            // mark exists
            banflag_exists = true;

            byte[] data = File.ReadAllBytes(filePath);
            if (data == null || data.Length == 0)
            {
                Debug.LogWarning($"banflag 文件为空: {filePath}");
            }
            else
            {
                // Documentation text normalized.
                string text = null;
                try
                {
                    text = Encoding.UTF8.GetString(data);
                }
                catch
                {
                    text = null;
                }

                bool looksLikeText = false;
                if (!string.IsNullOrEmpty(text))
                {
                    // Documentation text normalized.
                    int nonPrintable = 0;
                    int checkLen = Mathf.Min(256, text.Length);
                    for (int i = 0; i < checkLen; i++)
                    {
                        char c = text[i];
                        if (char.IsControl(c) && c != '\r' && c != '\n' && c != '\t') nonPrintable++;
                    }
                    looksLikeText = (nonPrintable == 0);
                }

                if (looksLikeText)
                {
                    Debug.Log($"已读取 banflag 文件: {filePath}\n内容:\n{text}");
                    // store the readable content for other scenes
                    banflagContent = text;
                }
                else
                {
                    // Documentation text normalized.
                    string base64 = System.Convert.ToBase64String(data);
                    Debug.Log($"已读取 banflag 文件（二进制）: {filePath}，长度={data.Length} bytes，Base64 前200字符预览:\n{(base64.Length > 200 ? base64.Substring(0,200) + "..." : base64)}");
                    banflagContent = $"[Binary Data] Length: {data.Length} bytes";
                }
            }

            // Documentation text normalized.
            string dir = Path.GetDirectoryName(filePath);
            if (string.IsNullOrEmpty(dir)) dir = banflag_filePath;

            // find JSON
            string foundJson = string.Empty;
            try
            {
                string[] jsons = Directory.GetFiles(dir, "*.json", SearchOption.TopDirectoryOnly);
                if (jsons != null && jsons.Length > 0)
                {
                    foundJson = jsons[0];
                }
            }
            catch { }

            // find audio: mp3, wav, ogg (in that priority)
            string foundAudio = string.Empty;
            try
            {
                string[] exts = new string[] { "*.mp3", "*.wav", "*.ogg" };
                foreach (var pat in exts)
                {
                    string[] matches = Directory.GetFiles(dir, pat, SearchOption.TopDirectoryOnly);
                    if (matches != null && matches.Length > 0)
                    {
                        foundAudio = matches[0];
                        break;
                    }
                }
            }
            catch { }

            // find image: jpg/jpeg, png (priority jpg then png)
            string foundImage = string.Empty;
            try
            {
                string[] imgExts = new string[] { "*.jpg", "*.jpeg", "*.png" };
                foreach (var pat in imgExts)
                {
                    string[] matches = Directory.GetFiles(dir, pat, SearchOption.TopDirectoryOnly);
                    if (matches != null && matches.Length > 0)
                    {
                        foundImage = matches[0];
                        break;
                    }
                }
            }
            catch { }

            // normalize and assign
            testmode_beatmapJSON_path = string.IsNullOrEmpty(foundJson) ? string.Empty : NormalizeToForwardSlashes(foundJson);
            testmode_audioFile_path = string.IsNullOrEmpty(foundAudio) ? string.Empty : NormalizeToForwardSlashes(foundAudio);
            testmode_bgPicFile_path = string.IsNullOrEmpty(foundImage) ? string.Empty : NormalizeToForwardSlashes(foundImage);

            // Debug the normalized paths
            Debug.Log($"banflag_exists={banflag_exists}");
            Debug.Log($"testmode_beatmapJSON_path = {testmode_beatmapJSON_path}");
            Debug.Log($"testmode_audioFile_path   = {testmode_audioFile_path}");
            Debug.Log($"testmode_bgPicFile_path   = {testmode_bgPicFile_path}");

            UpdateStatus("Banflag found", Color.green);

            return banflag_exists;
        }
        catch (System.Exception ex)
        {
            Debug.LogError($"读取 banflag 文件时发生错误: {ex}");
            UpdateStatus("Error reading banflag", Color.red);
            // ensure flags cleared on error
            banflag_exists = false;
            testmode_audioFile_path = string.Empty;
            testmode_bgPicFile_path = string.Empty;
            testmode_beatmapJSON_path = string.Empty;
            banflagContent = string.Empty;
            return false;
        }
    }
}